I had used the dTTP to do the PCR before, but now I had changed to use the dUTP and the PCR product can not be generated. Does any one know how the PCR can work which the nucleotide used is dUTP.

You have to be sure that the thermostable polymerase that you're using will incorporate dUTP into DNA, some enzymes like Pfx polymerase will not. I would also suggest using double the concentrations of dUTP in your reactions since Taq tends to have a lower affinity for dUTP. Good luck.

I have the same problem ... I can't get PCR products for AT rich sequences using dUTP instead of dTTP
I tried
* lowering annealing temperature
* Increasing dUTP concentration (twice as high as normal dNTPs)
* Trying different enzymes

Does anybody knows about an enzyme (or something else) that may solve this PCR problem?

Kind regards
Tim

You may want to try Tth polymerase, I have some success with this polymerase although it's still no complete guarantee ...

You could also use only a small amount of dUTP in a mix with near-normal amounts of dTTP, if the purpose is to allow removal of PCR product as potential templates in other reactions. You only need a few dUTP incorporated to allow enzymatic destruction of the template.
But perhaps you have some other reason for using dUTP in the PCR reaction.

My experience is dUTP doesn't work as well as dTTP especially with longer PCR products. Why are you doing the PCR with dUTP?

dUTP incorporates about 4 fold more difficult than dTTP. If your are working with all general RNA guidelines you shouldn't really need the dUTP unless you're working in a human diagnostic situation or have a confirmed contamination case.
If you don't use UNG every time than working with dUTP is actually quite useless.
If you're looking for enzymes which will work good with dUTP I suggest you look at suppliers of qpcr MM with the dUTP in it. The Enzymes are usually Hotstarts. Take a look at Abgene, ABI and Eurogentec.

good luck ,
Guy